Scientists have been unable to quantify the impact of ocean eddies so far because the exact boundaries of these swirling bodies have remained undetectable. However, researchers writing in the Journal of Fluid Mechanics say they have developed a new mathematical technique to find water-transporting eddies with coherent boundaries.

Researchers found that coherent eddies behaved like black holes. The researchers were able to observe a point around the eddies equivalent to a phenomenon called a photon sphere in a black hole. Photon spheres are created when light is far enough from the perimeter of the black hole that instead of being drawn down the black hole in a spiral, the light forms a circular orbit around the black hole itself.

Similar closed barriers around certain ocean eddies were identified by Haller and Beron-Vera.

"In these barriers, fluid particles move around in closed loops - similar to the path of light in a photon sphere. And as in a black hole, nothing can escape from the inside of these loops, not even water," the researchers wrote in a statement. "It is precisely these barriers that help to identify coherent ocean eddies in the vast amount of observational data available."